Every other input here exists because someone chose to publish it. Orbital observation does not: a site is imaged whether or not its operator has filed anything, on a cadence set by orbits rather than by reporting calendars. For anything under construction, that is often the only current source there is.
It is also the source that resolves disputes between the others. When a permit says one thing and a corporate statement says another, the slab either exists or it does not - which is why it carries disproportionate weight in entity resolution.